* {
    margin: 0;
    padding: 0;
}

h1 {
    margin: 40px 0 80px;
}

body {
    text-align: center;
    background-color: #f2f2f2;
}

main {
    width: 80%;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
}

.item {
    width: 150px;
    height: 150px;
    margin: 10px;
}

.item a {
    background-color: #fff;
    border-radius: 32px;
    display: inline-block;
    width: 100%;
    height: 100%;
    line-height: 150px;
    text-decoration: none;
    color: rgba(0,0,0,.8);
    font-size: 28px;
    box-shadow: 2px 3px 7px rgba(0,0,0,.1);
}

@media screen and (max-width: 900px) {
    main {
        width: 100%;
    }
}